EUI-2976: ExUI strategic solution

.eslintrc.js

@@ -0,0 +1,13 @@
+module.exports = {
+  "extends": "airbnb-base",
+  "env": {
+    "mocha": true,
+    "jasmine": true
+  },
+  "rules": {
+    "comma-dangle": 0,
+    "arrow-body-style": 0,
+    "no-param-reassign": [ 2, { props: false } ],
+    "linebreak-style": [ "error", process.platform === 'win32' ? 'windows' : 'unix' ]
+  }
+}

RELEASE-NOTES.md

@@ -0,0 +1,4 @@
+## RELEASE NOTES
+
+### Version 0.1.0-socket-alpha
+**EUI-2976** Socket-based Activity Tracking.

app.js

@@ -1,7 +1,6 @@
 const healthcheck = require('@hmcts/nodejs-healthcheck');
 const express = require('express');
 const logger = require('morgan');
-const bodyParser = require('body-parser');
 const config = require('config');
 const debug = require('debug')('ccd-case-activity-api:app');
 const enableAppInsights = require('./app/app-insights/app-insights');
@@ -43,9 +42,9 @@ if (config.util.getEnv('NODE_ENV') === 'test') {
 debug(`starting application with environment: ${config.util.getEnv('NODE_ENV')}`);
 
 app.use(corsHandler);
-app.use(bodyParser.json());
-app.use(bodyParser.urlencoded({ extended: false }));
-app.use(bodyParser.text());
+app.use(express.json());
+app.use(express.urlencoded({ extended: false }));
+app.use(express.text());
 app.use(authCheckerUserOnlyFilter);
 
 app.use('/', activity);

app/health.js

@@ -14,5 +14,4 @@ const activityHealth = healthcheck.configure({
       .catch(() => healthcheck.down())),
   },
 });
-
 module.exports = activityHealth;

app/job/store-cleanup-job.js

@@ -1,17 +1,15 @@
 const cron = require('node-cron');
 const debug = require('debug')('ccd-case-activity-api:store-cleanup-job');
-const moment = require('moment');
 const config = require('config');
 const redis = require('../redis/redis-client');
 
 const { logPipelineFailures } = redis;
-const now = () => moment().valueOf();
 const REDIS_ACTIVITY_KEY_PREFIX = config.get('redis.keyPrefix');
 
-const scanExistingCasesKeys = (f) => {
+const scanExistingCasesKeys = (f, prefix) => {
   const stream = redis.scanStream({
     // only returns keys following the pattern
-    match: `${REDIS_ACTIVITY_KEY_PREFIX}case:*`,
+    match: `${REDIS_ACTIVITY_KEY_PREFIX}${prefix}:*`,
     // returns approximately 100 elements per call
     count: 100,
   });
@@ -28,18 +26,17 @@ const scanExistingCasesKeys = (f) => {
   });
 };
 
-const getCasesWithActivities = (f) => scanExistingCasesKeys(f);
+const getCasesWithActivities = (f, prefix) => scanExistingCasesKeys(f, prefix);
 
-const cleanupActivitiesCommand = (key) => ['zremrangebyscore', key, '-inf', now()];
+const cleanupActivitiesCommand = (key) => ['zremrangebyscore', key, '-inf', Date.now()];
 
 const pipeline = (cases) => {
   const commands = cases.map((caseKey) => cleanupActivitiesCommand(caseKey));
   debug(`created cleanup pipeline: ${commands}`);
   return redis.pipeline(commands);
 };
 
-const storeCleanup = () => {
-  debug('store cleanup starting...');
+const cleanCasesWithPrefix = (prefix) => {
   getCasesWithActivities((cases) => {
     // scan returns the prefixed keys. Remove them since the redis client will add it back
     const casesWithoutPrefix = cases.map((k) => k.replace(REDIS_ACTIVITY_KEY_PREFIX, ''));
@@ -50,7 +47,13 @@ const storeCleanup = () => {
       .catch((err) => {
         debug('Error in getCasesWithActivities', err.message);
       });
-  });
+  }, prefix);
+};
+
+const storeCleanup = () => {
+  debug('store cleanup starting...');
+  cleanCasesWithPrefix('case'); // Cases via RESTful interface.
+  cleanCasesWithPrefix('c'); // Cases via socket interface.
 };
 
 exports.start = (crontab) => {

app/redis/instantiator.js

@@ -0,0 +1,46 @@
+const config = require('config');
+const Redis = require('ioredis');
+
+const ERROR = 0;
+const RESULT = 1;
+const ENV = config.util.getEnv('NODE_ENV');
+
+module.exports = (debug) => {
+  const redis = new Redis({
+    port: config.get('redis.port'),
+    host: config.get('redis.host'),
+    password: config.get('secrets.ccd.activity-redis-password'),
+    tls: config.get('redis.ssl'),
+    keyPrefix: config.get('redis.keyPrefix'),
+    // log unhandled redis errors
+    showFriendlyErrorStack: ENV === 'test' || ENV === 'dev',
+  });
+
+  /* redis pipeline returns a reply of the form [[op1error, op1result], [op2error, op2result], ...].
+    error is null in case of success */
+  redis.logPipelineFailures = (plOutcome, message) => {
+    if (Array.isArray(plOutcome)) {
+      const operationsFailureOutcome = plOutcome.map((operationOutcome) => operationOutcome[ERROR]);
+      const failures = operationsFailureOutcome.filter((element) => element !== null);
+      failures.forEach((f) => debug(`${message}: ${f}`));
+    }
+    return plOutcome;
+  };
+
+  redis.extractPipelineResults = (pipelineOutcome) => {
+    const results = pipelineOutcome.map((operationOutcome) => operationOutcome[RESULT]);
+    debug(`pipeline results: ${results}`);
+    return results;
+  };
+
+  redis
+    .on('error', (err) => {
+      // eslint-disable-next-line no-console
+      debug(`Redis error: ${err.message}`);
+    }).on('connect', () => {
+    // eslint-disable-next-line no-console
+      debug('connected to Redis');
+    });
+
+  return redis;
+};

app/redis/redis-client.js

@@ -1,47 +1,3 @@
-const config = require('config');
 const debug = require('debug')('ccd-case-activity-api:redis-client');
-const Redis = require('ioredis');
 
-const ERROR = 0;
-const RESULT = 1;
-const ENV = config.util.getEnv('NODE_ENV');
-
-const redis = new Redis({
-  port: config.get('redis.port'),
-  host: config.get('redis.host'),
-  password: config.get('secrets.ccd.activity-redis-password'),
-  tls: config.get('redis.ssl'),
-  keyPrefix: config.get('redis.keyPrefix'),
-  // log unhandled redis errors
-  showFriendlyErrorStack: ENV === 'test' || ENV === 'dev',
-});
-
-/* redis pipeline returns a reply of the form [[op1error, op1result], [op2error, op2result], ...].
-   error is null in case of success */
-redis.logPipelineFailures = (plOutcome, message) => {
-  if (Array.isArray(plOutcome)) {
-    const operationsFailureOutcome = plOutcome.map((operationOutcome) => operationOutcome[ERROR]);
-    const failures = operationsFailureOutcome.filter((element) => element !== null);
-    failures.forEach((f) => debug(`${message}: ${f}`));
-  } else {
-    debug(`${plOutcome} is not an Array...`);
-  }
-  return plOutcome;
-};
-
-redis.extractPipelineResults = (pipelineOutcome) => {
-  const results = pipelineOutcome.map((operationOutcome) => operationOutcome[RESULT]);
-  debug(`pipeline results: ${results}`);
-  return results;
-};
-
-redis
-  .on('error', (err) => {
-    // eslint-disable-next-line no-console
-    console.log(`Redis error: ${err.message}`);
-  }).on('connect', () => {
-  // eslint-disable-next-line no-console
-    console.log('connected to Redis');
-  });
-
-module.exports = redis;
+module.exports = require('./instantiator')(debug);

app/routes/validate-request.js

@@ -1,3 +1,5 @@
+const debug = require('debug')('ccd-case-activity-api:validate-request');
+
 const validateRequest = (schema, value) => (req, res, next) => {
   const { error } = schema.validate(value);
   const valid = error == null;
@@ -6,7 +8,7 @@ const validateRequest = (schema, value) => (req, res, next) => {
   } else {
     const { details } = error;
     const message = details.map((i) => i.message).join(',');
-    console.log('error', message);
+    debug(`error ${message}`);
     res.status(400).json({ error: message });
   }
 };

app/security/cors.js

@@ -2,7 +2,8 @@ const config = require('config');
 const sanitize = require('../util/sanitize');
 
 const createWhitelistValidator = (val) => {
-  const whitelist = config.get('security.cors_origin_whitelist').split(',');
+  const configValue = config.get('security.cors_origin_whitelist') || '';
+  const whitelist = configValue.split(',');
   for (let i = 0; i < whitelist.length; i += 1) {
     if (val === whitelist[i]) {
       return true;

app/service/activity-service.js

@@ -1,4 +1,3 @@
-const moment = require('moment');
 const debug = require('debug')('ccd-case-activity-api:activity-service');
 
 module.exports = (config, redis, ttlScoreGenerator) => {
@@ -31,7 +30,7 @@ module.exports = (config, redis, ttlScoreGenerator) => {
     const uniqueUserIds = [];
     let caseViewers = [];
     let caseEditors = [];
-    const now = moment.now();
+    const now = Date.now();
     const getUserDetails = () => redis.pipeline(uniqueUserIds.map((userId) => ['get', `user:${userId}`])).exec();
     const extractUniqueUserIds = (result) => {
       result.forEach((item) => {

app/service/ttl-score-generator.js

@@ -1,10 +1,10 @@
 const config = require('config');
-const moment = require('moment');
 const debug = require('debug')('ccd-case-activity-api:score-generator');
 
 exports.getScore = () => {
-  const now = moment();
-  const score = now.add(config.get('redis.activityTtlSec'), 'seconds').valueOf();
-  debug(`generated score out of current timestamp '${now.valueOf()}' plus ${config.get('redis.activityTtlSec')} sec`);
+  const now = Date.now();
+  const ttl = parseInt(config.get('redis.activityTtlSec'), 10) || 0;
+  const score = now + (ttl * 1000);
+  debug(`generated score out of current timestamp '${now}' plus ${ttl} sec`);
   return score;
 };

app/socket/index.js

@@ -0,0 +1,37 @@
+const config = require('config');
+const IORouter = require('socket.io-router-middleware');
+const SocketIO = require('socket.io');
+
+const ActivityService = require('./service/activity-service');
+const Handlers = require('./service/handlers');
+const pubSub = require('./redis/pub-sub')();
+const router = require('./router');
+
+/**
+ * Sets up a series of routes for a "socket" endpoint, that
+ * leverages socket.io and will more than likely use long polling
+ * instead of websockets as the latter isn't supported by Azure
+ * Front Door.
+ *
+ * The behaviour is the same, though.
+ *
+ * TODO:
+ *   * Some sort of auth / get the credentials when the user connects.
+ */
+module.exports = (server, redis) => {
+  const activityService = ActivityService(config, redis);
+  const socketServer = SocketIO(server, {
+    allowEIO3: true,
+    cors: {
+      origin: '*',
+      methods: ['GET', 'POST'],
+      credentials: true
+    },
+  });
+  const handlers = Handlers(activityService, socketServer);
+  const watcher = redis.duplicate();
+  pubSub.init(watcher, handlers.notify);
+  router.init(socketServer, new IORouter(), handlers);
+
+  return { socketServer, activityService, handlers };
+};

app/socket/redis/keys.js

@@ -0,0 +1,23 @@
+const keys = {
+  prefixes: {
+    case: 'c',
+    socket: 's',
+    user: 'u'
+  },
+  case: {
+    view: (caseId) => keys.compile('case', caseId, 'viewers'),
+    edit: (caseId) => keys.compile('case', caseId, 'editors'),
+    base: (caseId) => keys.compile('case', caseId),
+  },
+  user: (userId) => keys.compile('user', userId),
+  socket: (socketId) => keys.compile('socket', socketId),
+  compile: (prefix, value, suffix) => {
+    const key = `${keys.prefixes[prefix]}:${value}`;
+    if (suffix) {
+      return `${key}:${suffix}`;
+    }
+    return key;
+  }
+};
+
+module.exports = keys;

app/socket/redis/pub-sub.js

@@ -0,0 +1,15 @@
+const keys = require('./keys');
+
+module.exports = () => {
+  return {
+    init: (watcher, caseNotifier) => {
+      if (watcher && typeof caseNotifier === 'function') {
+        watcher.psubscribe(`${keys.prefixes.case}:*`);
+        watcher.on('pmessage', (_, room) => {
+          const caseId = room.replace(`${keys.prefixes.case}:`, '');
+          caseNotifier(caseId);
+        });
+      }
+    }
+  };
+};